People using a wireless connection to access 1.58GB of data each month use more energy each year than a medium-sized fridge Photograph: Jennifer Byron/Getty Images

Phubbing (phone + snubbing) is a horrible portmanteau word for what some people feel is a fairly unpleasant type of behaviour: ignoring one's companions in favour of stabbing at the screen of a smartphone.

It's had its share of the limelight in the past few weeks thanks to a publicity campaign run by Alex Haigh, whose website, stopphubbing.com, suggests that checking Twitter instead of making eye contact with your mates at the bar could lead to the end of civilization as we know it.

But it seems that smartphones can be blamed for more than bad manners; they also create a significant carbon footprint, as they consume far more energy than most people realise. Research by Mark Mills, the chief executive of the Digital Power Group, suggests that people who use a wireless connection to access 2.8GB of data each week are using more energy each year than a medium-sized fridge, once charging, data usage and so on are all taken into account.

The problem is that most of this energy usage is hidden so people don't really think about it. Charging a phone uses very little energy – no more than a child's nightlight, Mills said – but that's only a small fragment of its overall footprint.

"If you start using the phone for phubbing you are using 10 times the amount of energy you use just plugging it in. And if you use it for video, it goes up another tenfold."

That's because the moment someone uses a phone (or a tablet, laptop or other computer) to access the internet they are also using the servers that are used to store and move data. "It's not that particular mobile phone models aren't energy efficient, it's that we use these devices to access cloud computing services, and this always-on IT culture requires huge data farms to be located around the country," said Peter Hopton, the founder of Iceotope, a green IT business that cools servers using liquid rather than air conditioning.

Here's Mills' analogy: "When you go and sit in your car and turn it on you are just using the energy in your gas tank. But when you use your smartphone you are connecting to computers all around the world and turning them on too. It's as if turning on your car turned on all the other cars in the car park as well."

The UK has the greatest concentration of data farms in the world, Hopton said, with a single server in a typical data centre creating the same carbon footprint each year as a Range Rover sport. Globally, the world's computing economy uses more energy each year than aviation.

But is cloud computing all bad? Research published recently in Scientific American suggests that, despite the energy used by data centres, cloud computing uses less energy than on-site alternatives. One simulation found that if all US businesses switched their email and other software to the cloud it would cut the amount of energy used for computing by 87%; this is mostly because companies' on-site hardware tends to be fairly inefficient.

Mills argues that the findings of such research are accurate, as far as they go, but they miss a larger point. "If you have a business and in it you have a computer room and you do most of your email, account management and so on using those computers, you will find that switching to the cloud … will use less energy," he said. "That's because the cloud can optimise the use of computers. It's basically catching the bus instead of using the car.

"But the calculations are a bit misleading. Doing the exact same thing in the cloud will use less energy and is cheaper, so what happens is that people do not do the same thing, they do lots more of it and they do new things, which results in more energy being used overall.

"In the last 10 years computing has got about a thousand times more energy efficient but the amount of digital traffic has increased by five or even ten thousand times."

This brings us back nicely to smartphones: they're using more energy (and ruining polite conversation) simply because each new generation is so much better than the one before. They offer the possibility of doing more with them, and we take them up on it. This is why phone companies encourage us to upgrade: they know that moving up the scale increases the amount of data consumers use.

This knowledge offers committed carbon-minimisers the only effective way of cutting back: stop using your smartphone or any other computer to connect to the internet. "Don't do Facebook, don't stream video, don't use Instagram or Google Maps," said Mills. Or at least consider using non-cloud options for your home computing wherever possible, suggested Hopton. For example, back up your information to a portable hard drive in your house (which you can then turn off) rather than to servers in the cloud (which are always on).

But there's no need for the anti-phubbing brigade to get too excited: it's unlikely that many people will go as far as dumping all their always-on devices. "It's part of life now," Hopton said. "People feel lost when they don't have a phone delivering Facebook updates and pictures of cats whenever they want them."